“Ahhhh?” said Bill Lightning. “Don’t you mean ‘Arrrgh’? As in ‘Arrgh, this twenty-tentacles monster is trying to eat me.”

“No, it’s definitely ‘Ahhhh’,” said Cassie. “As in ‘Ahhh, what a lovely day we be having.”

“What a lovely day we are having,” muttered Tom, looking up from his book.

“There you go,” said Cassie triumphantly. “Ahhhh!”

But nobody was listening because Bill Lightning had already launched into the tale of how the Onion defeated the Dreaded Great Sea Beast of the South…

We were sailing around the Andromeda Ocean in the south when we saw the island. “What do you think, Captain?” asked Tim Burre, who never liked new places. “It looks a bit odd.”

It did look odd. Most islands are wiggly round the edges, but this one looked quite smooth and round. It was mainly flat, rising up into a shallow hill in the middle, and the slopes were covered in a thick, dark green, mossy grass. It looked to be deserted.

“Let’s go ashore,” said Cassie.

We all cheered. We’d been sailing for over a month without a break. For the past week, the only thing we’d had to eat was fish. Fish cereal for breakfast, fish sandwiches for lunch, and then as a special treat for tea we had fish sausages with fishy mashed potato and fish jelly and ice-cream for afters. And the only seasoning she had left was pepper. If you want to try melted, fish-flavoured ice-cream that makes you sneeze, I have some advice: just don’t.

About half the crew stayed on the ship and the rest of us made our way ashore. The island was very strange indeed. The grass felt springy but the ground was quite hard underneath.

It was starting to get dark, so we settled down for the night. I found some bits of driftwood around the shore and we made a fire. While Trudi tried cooking some of the grass to see if it would make it taste better, the rest of us just sat. It was peaceful, doing nothing, watching the fire burn and the sun sink down into the sea.

Trudi tasted her grass casserole. “Too bland,” she said and she scrabbled around in her pockets and found a big bag of pepper.

Right at that moment, the ground shook. It was followed by another tremor, more violent this time, and then the island started to move.

And we saw that it wasn’t an island at all. It was a monster. Half a mile across, with tentacles flapping everywhere.

This wasn’t any old monster. This was the biggest, the deadliest, the most-tentacled monster of them all. We’d heard all the stories about it: it ate a hundred ships for breakfast every day, and another fifty for supper. It was as big as an island with a thousand tentacles and ten thousand eyes, but nobody really knew what it looked like, because no one had ever seen it and survived.

It was the Dreaded Great Sea Beast of the South.

The fire scattered and so did we. The Dreaded Beast scrabbled at its skin with its tentacles, just like it was trying to scratch an itch on its back.

“Back to the ship!” Cassie cried and we all ran.

Tentacles thrashed around us and the great body jerked and heaved. Pirates tumbled into the sea. I drew my cutlass and started cutting through the tentacles, but for every one that fell into the sea, another two swarmed in. I ran up one and jumped. For a second or two, I thought I was going to land in the sea, but then I smacked right into the deck of the Onion.

Tentacles were grabbing at the ship now. This didn’t look good.

“What do we do?” shouted Trudi.

“The monster woke up when we lit that fire,” said Cassie. “Is it afraid of fire?”

I doubted it was afraid of anything, but I grabbed a rope dipped the end of it in oil, and set fire to it. (Don’t try this at home – it’s dangerous.)

I ran at the monster, which didn’t actually take long because it was right on top of us.

“Take that!” I cried, and whacked it with the burning rope.

Nothing.

The many tentacles kept slapping the ship. One of them caught fire briefly but the monster didn’t even seem to notice. More tentacles wrapped around the main mast and started to pull. We were going to go over into the sea, that’s if the monster didn’t tear the ship apart first.

It looked as though we were doomed. The monster hadn’t minded all of us tramping over its head and setting up camp there. It hadn’t even moved when we lit a fire. It didn’t wake until…

“Pepper!” I shouted. The monster had slept peacefully until Trudi had got her pepper out.

“Wait here,” said Trudi, and she raced down the steps below deck.

She appeared again a minute later with a saucepan on her head and a large earthenware pot. By then, the beast had grabbed both ends of the Onion and it was trying to tear the ship in half. A monstrous head rose out of the water, covered with seaweed and a great beak of a mouth opened up, ready to swallow us whole.

Trudi hurled the pepper straight into the monster’s mouth.

The dreaded beast paused.

Its mouth opened wide and then, instead of swallowing us, it sneezed.

All the tentacles let go and the Onion shot backwards. The beast bellowed in rage and started after us but before it could reach us, it sneezed again and the blast sent us racing away, far out of reach of the angry tentacles.

“Well,” said Cassie, looking around at us all, covered in bits of tentacle and slime from the monster’s sneeze, “that could have been worse.”

As for the Dreaded Great Sea Beast of the South, it disappeared under the waves, and to this day it has never been seen again. Maybe one day it’ll come back.